1. Field of the Invention
The present invention relates to a method for detecting the location of leaks in subsurface pipelines, and particularly to conserving energy, such as fuel or natural gas, or conserving water, desalinated or purified, transported through these pipelines by employing an apparatus that uses radio frequency identification (RFID) tags inside the buried pipelines to locate the specific site of leakage of the fuel, gas or water from the pipeline, thereby preserving these natural resources. The invention reduces the unnecessary use of energy to replace the processed water or fossil fuel that is lost through leakage under the surface, and prevents resulting environmental contamination from leakage for which the location is not detected.
2. Description of the Related Art
In regions of the world where fresh water is virtually non-existent, the principal source of water is through the energy intensive desalination of seawater. Large amounts of fossil fuels are used in the desalination process, and pipelines of relatively expensive drinking water are buried below the surface to transport the water to inland populations. Unfortunately, leaks in these pipelines are common and are not easily located. It has been reported that 30% of the water transported across the Kingdom of Saudi Arabia (KSA) is lost through leakage. The need to conserve this limited resource is compounded by the additional cost to replenish the leaked water by producing additional desalinated water through even further use of fuel. Leaks in water pipelines, while far from being a new problem, are escalating with increasing population growth in the desert areas. The undetected leaks also expose the water flowing through these pipes to subsurface contaminants and carcinogenic agents that may exist under the surface.
Similarly, leaks in oil and natural gas pipelines cause environmentally harmful damage to surrounding areas, as well as loss of valuable energy resources transported by pipelines. While the environmental damage associated with the loss of oil and natural gas (a potent green house gas) is more widely reported, significant losses of processed gas, oil or water require a corresponding additional amount of energy generation, resulting in additional pollution and millions of dollars in wasted energy. Furthermore, the problems of leakage can result in hazardous contaminants into the fuel or gas, and water distributed worldwide. It has been reported by a group of medical doctors from the department of Oncology, King Faisal Specialist Hospital, Riyadh, Saudi Arabia, that water contamination causing esophageal cancer at the Qassim region in the Kingdom of Saudi Arabia constitutes a major health risk and problem there. Furthermore, leaks can cause major infrastructure problems by undermining ground stability and, in the process, damaging roads and buildings.
To address these very significant environmental issues, a great deal of research and technology development has been accomplished in the last two decades to detect leaks in pipelines. The terms leak or leakage, when referring to a pipeline, should be taken to include any pipeline defect capable of allowing leakage, even if that pipeline defect is not leaking at any one particular time. Leak detection devices include acoustic leak detection, leak noise correlators, surface listening devices, ground penetrating radar detection methods, and chemical tracing methods, as well as X-Ray and infrared radiation methods. In a recent study, the use of leak noise correlators proved unreliable and costly, in addition to being time-consuming. The use of electronic sound detectors proved more reliable and cost effective. The detectors were placed manually as close as possible to the pipelines. However, sound detectors have proven to be a less than ideal solution.
More recently, robotic detectors have been developed to travel inside pipelines to perform leak detection. Some of these devices are known as conventional pipe inspection units, such as pipe inspection gages (PIGs) or present free-swimming robots. However, pipeline networks can be many hundreds or thousands of miles in length and can present widely varying currents and other conditions to these PIGs. Furthermore, the precise and repeatable determination of the location of leakage within each pipe section is important to analyzing and preventing or mitigating pipeline leakage, especially since many of these leaks are in difficult to identify locations buried underground. Thus, a method of conserving energy and water using an apparatus to locate leaks in subsurface pipelines solving the aforementioned problems is desired.